Tool box talk questions

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# Hand Tool Ergonomics - Health Hazards (cont.) ## Awkward working positions and body postures (cont.) When the hand holds and uses a tool in an awkward position, it has less strength and is consequently more susceptible to soreness and eventual injury. If the arm is uncomfortable, the rest of the body is likely to be so as well, because it is natural to compensate for discomfort by trying to re-align the body by bending the back, rounding the shoulders, tilting the neck, and so on. Awkward positions of the upper body considerably increase the effort needed to complete the task. The resulting fatigue, discomfort, and pain add further to the risk of developing injury. ## Tissue compression from forceful grips Typically, using a hand tool requires a firm grip. The resulting compression of soft tissue in the palm and fingers may obstruct blood circulation, resulting in numbness and tingling. Blisters are also common due to friction between the palm of the hand and the handle of the tool. ## Vibration Certain heavy tools, such as a chipping hammer, can produce significant vibration, which is responsible for hand-arm vibration syndrome (HAVS), more commonly known as white finger or Raynaud's syndrome. Fact sheet confirmed current: 2023-09-26 Fact sheet last revised: 2017-12-01 ## Disclaimer Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information. Hand Tool Ergonomics - Health Hazards CCOHS

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# Hand Tool Ergonomics - Workspace Design (cont.) ## How can work space design help prevent work-related musculoskeletal disorders (WMSDs) resulting from the improper use of hand tools? (cont.) Avoid bending over your work; instead, keep your back straight and, if possible, elevate the work area or task to a comfortable level. Keep your elbows close to the body, and reduce the need to stretch your arms overhead or out in front of you. Tool extensions can help where it is difficult to reach the object of work. Using a stepladder or step stool can improve the working body position, where the task requires elevating your arms above the shoulder. At the same time, frequent stretching breaks will relieve any built-up muscle tension. If standing, distribute your weight evenly between the feet. Use a footstool or rail to rest your legs, and shift from one to the other periodically. Proper chairs and sit/stand stools offer support during many hand tool tasks -- read more about these in our OSH Answers documents on Working in a Sitting Position, and Working in a Standing Position. Consider the use of anti-fatigue mats. ## How should one design the workstation for precision work? - Provide the worker with a height-adjustable workstation (Figure 1a) - For a fixed-height workbench: - Provide work platforms to accommodate shorter workers; - Raise the work surface for taller workers. 30 cm - Figure 1a - Provide sufficient leg clearance to allow the worker to get close to the work object, thereby reducing the need to bend the torso. - Provide a footrest as foot support to improve body balance and minimize the static load on the worker's back. Hand Tool Ergonomics - Workspace Design CCOHS

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Hand Tools # Hand Tools - General Hand Tool Operation ## On this page What are some basic tips when using hand tools? What should I avoid when using hand tools? ## What are some basic tips when using hand tools? - Make sure that employees are properly trained in the safe use of hand tools. - Always provide training on how to choose the right tool for the job, how to correctly use each tool, and how to identify when tools need repair. Select the right tool for the job. Substitutes increase the chance of having an accident. - Use tools designed to allow the wrist to stay straight. Avoid using hand tools with your wrist bent. - Use good quality tools. - Keep tools in good condition at all times. - Inspect tools for defects before use. Replace or repair defective tools. - Keep cutting tools sharp and cover sharp edges with a suitable covering to protect the tool and to prevent injuries from unintended contact. - Replace cracked, splintered, or broken handles on files, hammers, screwdrivers, or sledges. - Make sure that the handles of tools like hammers and axes fit tightly into the head of the tool. - Replace worn jaws on wrenches, pipe tools and pliers. - Redress burred or mushroomed heads of striking tools. - Pull on a wrench or pliers. Never push unless you hold the tool with your palm open. - Point sharp tools (e.g., saws, chisels, knives) laying on benches away from aisles, and handles should not extend over the edge of the bench top. Hand Tools - General Hand Tool Operation CCOHS

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# Hand Tool Ergonomics - Tool Design (cont.) ## Weight of the tool (cont.) C Center of Gravity Figure 1 It is also important that the centre of gravity be aligned with the centre of the gripping hand. In other words, tools should feel "easy" to hold either in an upright position or in the position it will be used (i.e., pointing down). For example, drills that are "front-heavy" will require effort (especially in the wrist and forearm) to hold in a usable position and should be avoided. The exception to this principle is a power hand tool, such as a grinder, that has to be heavy in order to reduce the force that the worker has to exert while using it. ## Handles With the exception of tools for precision work (e.g., watchmaking, microsurgery, carving), the handles and grips of hand tools should be designed for a power grip. A power grip means that the operator can align their fingers towards the palm, using their entire hand and allowing for a stronger grip. Pinch grip refers to holding an object between the thumb and fingers of a single hand. ## Handle shape Tools with "bent" or angled handles or tools with pistol grips are beneficial where the force is exerted in a straight line in the same direction as the straightened forearm and wrist, especially when the force must be applied horizontally (see Figures 2, 3, 4). Figure 2 Hand Tool Ergonomics - Tool Design CCOHS

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Hand Tool Ergonomics # Hand Tool Ergonomics - Health Hazards On this page What are the main health concerns in working with hand tools? What factors, when working with hand tools, can cause injury? ## What are the main health concerns in working with hand tools? Along with common injuries such as cuts, lacerations, and bruises, the frequent and prolonged use of hand tools can cause soreness, aches, pains, and fatigue. These injuries, which, when ignored, can lead to chronic musculoskeletal injuries (MSIs). The most common examples of these work-related musculoskeletal disorders (WMSDs) are tendonitis, tenosynovitis, bursitis, epicondylitis (tennis elbow), carpal tunnel syndrome and de Quervain's syndrome. You can find prevention tips in the documents listed above, as well as in other OSH Answers documents, including: - Working in a Sitting Position - Working in a Standing Position - Cabinet Manufacturing - Carpenter ## What factors, when working with hand tools, can cause injury? Several work factors can affect the health and performance of hand tool users. Major ones include: - static load on arms and upper body muscles - awkward working positions and body postures - tissue compression Hand Tool Ergonomics Health Hazards CCOHS

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# What ergonomic factors are unique to powered hand tools? (cont.) ## What should one remember when selecting and using hand tools? (cont.) The condition of tools is an important factor. Blunt or dull tools such as scissors, cutters, saws, and screwdriver tips, in fact, any tools in a poor state of repair, not only compromise safety but also increase (sometimes by a factor of ten) the effort needed to use them. Tools in poor condition should be discarded (with the exception of those few that can be restored to optimum condition, for example, a wood chisel or wood saw) and replaced with new ones. Fact sheet last revised: 2023-10-31 ## Disclaimer Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information. Hand Tool Ergonomics - Tool Design CCOHS

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# Hand Tool Ergonomics - Tool Design (cont.) ## Handle shape (cont.) Figure 3 Figure 4 Tools with straight handles are for tasks where the force is exerted perpendicular to the straightened forearm and wrist, for instance, when the force must be applied vertically. Shaped tools such as bent-handle tools are effective where most of the tasks are done in the same plane and height as the arm and hand and when only one or two other tools are used (see Figure 5). Figure 5 Hand Tool Ergonomics - Tool Design CCOHS

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# Hand Tool Ergonomics - Tool Design (cont.) ## Separation between handles (Span) (cont.) To ensure a good grip on a handle, sufficient friction must exist between the hand and the handle. This is particularly important where a considerable force must be applied with a sweaty hand. Hand tools should be made of non-slip, non-conductive and compressible materials. For example, textured rubber handles provide a good grip, reduce the effort needed to use the tool effectively, and prevent the tool from slipping out of the hand. Glossy coatings and highly polished handles should be avoided. The electrical and heat insulation properties of the handles are important for power hand tools. Handles made of plastics or compound rubber are recommended. Sharp edges and contours can be covered with cushioned tape to minimize lacerations. The table below summarizes some of the guidelines presented above. <table><tr><th colspan="3">Guidelines - Summary</th></tr><tr><td>Description</td><td>Guideline</td><td>Reason</td></tr><tr><td>Tool shape</td><td>Slightly contoured</td><td>Easy grip</td></tr><tr><td>Direction of force is in line with forearm and wrist (typically horizontal)</td><td>Bent handle</td><td>Minimal wrist deviation</td></tr><tr><td>Direction of force is perpendicular to forearm and wrist (typically vertical)</td><td>Straight handle</td><td>Minimal wrist deviation</td></tr><tr><td>Separation distance between handles (for crushing, gripping or clipping tools such as pliers or tongs)</td><td>65-90 mm (separation distance)</td><td>Maximum grip strength</td></tr><tr><td>Handle length</td><td>&gt; 100 mm</td><td>Keep contact out of palm</td></tr><tr><td>Handle diameter (power grip)</td><td>30-50 mm</td><td>Greater force and stability</td></tr><tr><td>Handle diameter (precision task)</td><td>8-16 mm</td><td>Greater control</td></tr><tr><td>Material and texture of handles</td><td>Non-slip non- conductive materials</td><td>For comfort and reduces effort required to use tool</…

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# Hand Tools - General Hand Tool Operation (cont.) ## What are some basic tips when using hand tools? (cont.) - Maintain tools carefully. Keep them clean and dry, and store them properly after each use. - Carry tools in a sturdy toolbox to and from the worksite. - Wear safety glasses or goggles, or a face shield (with safety glasses or goggles) and well-fitting gloves appropriate for the hazards to which you may be exposed when doing various tasks. Keep the work environment clean and tidy to avoid clutter, which may cause incidents. - Use a heavy belt or apron and hang tools pointed down at your sides, not behind your back. - Keep the work space tidy. Store tools properly when not in use. ## What should I avoid when using hand tools? - Do not use tools for jobs they are not intended to do. For example, do not use a slot screwdriver as a chisel, pry bar, wedge or punch, or wrenches as hammers. - Do not apply excessive force or pressure on tools. - Do not cut towards yourself when using cutting tools. - Do not hold the stock in the palm of your hand when using a cutting tool or a screwdriver. Always lay it on a workbench or in a vice. - Do not wear bulky gloves to operate hand tools. - Do not throw tools. Hand them, handle first, directly to other workers. - Do not carry tools in a way that interferes with using both hands on a ladder, while climbing on a structure, or when doing any hazardous work. If working on a ladder or scaffold, tools should be raised and lowered using a bucket and hand line. - Do not carry a sharp tool in your pocket. Hand Tools - General Hand Tool Operation CCOHS

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# Hand Tool Ergonomics - Job Design (cont.) ## Task variety (cont.) - Add more tasks to the job. - Assign a larger part of work to a team: workers form a team, and each team member shares several different tasks. ## Work pace A fast pace of work is a strong risk factor for WMSDs. If the pace is too fast, the muscles involved do not have enough time to recover from the effort and to restore sufficient energy to continue the work. - If the pace of work is imposed externally -- assembly line speed, for example -- adjust it to the speed that is acceptable for the slowest worker. - Incentive systems that reward for the quality of work naturally determine the "right" pace of work. - Incentive systems that reward for the amount or quantity of work increase the risk for WMSDs and, in the long run, will compromise quality as well. ## Work breaks The work break is a time period between tasks. Even short periods of time, literally seconds, that allow one to relax muscles involved in operating tools are important in preventing injuries. ## Rest breaks The rest break is the period after work stops. Besides allowing for refreshment, rest breaks can be used to stretch and relax. ## Adjustment period An adjustment or acclimatization period is the time needed to get "in shape" when returning to work after a long absence, or when starting a new job. It should allow one to refresh old work habits or get used to a new routine. An adjustment period is a very important element of injury prevention. Inexperienced and "new" workers, as well as "experienced workers" returning to work after a period of recovery and rehabilitation, are more prone than most workers to both injury and re-injury, so adjustment periods are a vitally important way to reintegrate them into the workflow. Training Hand Tool Ergonomics - Job Design CCOHS

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Hand Tool Ergonomics # Hand Tool Ergonomics - Job Design ## On this page How can job design help prevent work-related musculoskeletal disorders (WMSDs) that can result from using hand tools? ## How can job design help prevent work-related musculoskeletal disorders (WMSDs) that can result from using hand tools? People working at a correctly designed workstation and using the best available tools can still get injured. It happens where their work is poorly designed. Job design (or work organization) involves: - job content -- task variety - work pace - work breaks - rest breaks - adjustment or acclimatization time - training ## Task variety Jobs that involve using only one kind of tool for one or a few tasks that do not vary in the movements and muscles used can cause an overload of those muscles, ligaments, tendons or tissues. The resulting overload on the same part of the body can cause pain and injury. A greater variety of tasks allow for changing body position to distribute the workload over different parts of the body, and to give overtaxed muscles some relief and recovery time. Rotate tasks among workers; have workers move from one task to another according to a schedule. Ensure tasks are different in the type of movement and body parts used. Hand Tool Ergonomics - Job Design CCOHS

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# Hand Tool Ergonomics - Health Hazards (cont.) ## Static load (cont.) Static effort, that is, holding any strained position for a period of time, is a particularly undesirable component in any work situation. Static effort increases the pressure on both the muscles, as well as on tissues, tendons and ligaments. It also reduces blood flow, which causes localized fatigue at a much quicker rate than would be expected by performing dynamic work (involving movement). Statically loaded muscles are much more vulnerable to fatigue and subsequent injury than muscles which are performing dynamic work. Furthermore, muscles which are tired by static work take more than 10 times longer to recover from fatigue. ## Awkward working positions and body postures Hand tools are often (actually, more than often) used where the space is limited and access is difficult; see Figures 2a, 2b, 2c. Figure 2a Figure 2b Figure 2c Hand Tool Ergonomics - Health Hazards CCOHS

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CCOHSOCCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Hand Tool Ergonomics # Hand Tool Ergonomics - Tool Design ## On this page How can the risk of work-related musculoskeletal disorders (WMSDs) resulting from the use of hand tools be reduced? What are the major ergonomic concerns of a hand tool design? When should power tools be used? What ergonomic factors are unique to powered hand tools? What should one remember when selecting and using hand tools? How does hand tool maintenance reduce the risk of injuries? How can the risk of work-related musculoskeletal disorders (WMSDs) resulting from the use of hand tools be reduced? Tool design (weight, shape, fit to the user and the task), workstation design (size, shape and layout), and the way tasks are scheduled are all key factors in making hand tool use safe and risk-free. An effective prevention strategy must address all aspects at the same time. ## What are the major ergonomic concerns of a hand tool design? ## Weight of the tool Ideally, a worker should be able to operate a tool with one hand. The weight of the tool may depend on the use: 2.3 kg (5 lb) if the hand tool will be used away from the body or above shoulder height. - 1.4 kg (3 lb) or less for tools operated with one hand - 0.4kg (1 lb) for precision tools to allow for good control. Tools above these recommendations should be supported with a counterbalance, tool holder, articulating arm, or straps as appropriate. Hand Tool Ergonomics - Tool Design CCOHS